Monroe County, Illinois
Monroe County: county in Illinois, United States
About
Monroe County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 32,957 and a population density of 32 people per km². After 10 years in 2020 county had an estimated population of 34,739 inhabitants. Its county seat is Waterloo. The county was created 210 years ago in 1816.
County Snapshot
Monroe County at a glance
Monroe County currently has 6 quality-checked populated place pages linked on MapSof, making it easier to jump from the county overview into local city pages.
Mapped populated places
6
These counts use a stricter populated-place filter so the main lists stay focused on real city and town pages.
Illinois counties
102
Open related pagesLargest city
ColumbiaPopulation 10,627
Top linked places
Quick Facts about Monroe County
| Population | 34,739 (2020) |
| Country | United States of America |
| State | Illinois (United States) |
| Different from | Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County, Monroe County |
| Area | 1030 km2 |
| Water as percent of area | 3.3% |
| Land as percent of area | 96.7% |
| Latitude & Longitude | 38.2787,-90.1774 |
| Named for | James Monroe |
| Capital | Waterloo |
| Establishment | January 06, 1816 |
| Time Zone | America/Chicago |
| Local time | 17:58:15 (18th April 2026) |
| Density | 34 Pop. per km² as of 2020 |
| Population growth | 5.13% (2010-2020) |
| Weather | 61℉ Chance Rain Showers 7-days weather |
Geography
Monroe County is located at 38°16'43"N 90°10'39"W (38.2786500, -90.1773800). It has 4 neighbors: Randolph County, Saint Clair County, Jefferson County and Sainte Genevieve County.
Monroe County map
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The largest city of Monroe County is Columbia with a population of 10,627. Other cities include, Waterloo population 10,536, Valmeyer population 1,238, Hecker population 474 and Maeystown population 162. See all Monroe County cities & populated places.
Monroe County Populated Places
Cities, towns, neighborhoods & other populated places in Monroe County.
| City Name | Population | Title |
|---|---|---|
| Columbia | 10,627 | City in Illinois, United States |
| Waterloo | 10,536 | City in Illinois |
| Valmeyer | 1,238 | Human settlement in Illinois, United States of America |
| Hecker | 474 | Village in United States of America |
| Maeystown | 162 | Human settlement in United States of America |
| Fults | 28 | Village in United States of America |
Weather
A chance of rain showers. Partly sunny. High near 61, with temperatures falling to around 57 in the afternoon. Northwest wind around 15 mph, with gust...
7-Day ForecastOfficial website of Monroe County
Official WebsiteDemographics
The population of Monroe County increased by 5.13% in 10 years.
| Year | Population | % Change | Method |
|---|---|---|---|
| 2010 | 32,957 | - | census |
| 2011 | 33,214 | 0.77% | estimation process |
| 2012 | 33,260 | 0.14% | estimation process |
| 2013 | 33,457 | 0.59% | estimation process |
| 2014 | 33,540 | 0.25% | estimation process |
| 2015 | 33,739 | 0.59% | estimation process |
| 2016 | 33,913 | 0.51% | estimation process |
| 2017 | 34,179 | 0.78% | estimation process |
| 2018 | 34,373 | 0.56% | estimation process |
| 2019 | 34,637 | 0.76% | estimation process |
| 2020 | 34,739 | 0.29% | estimation process |
People born in Monroe County (4)
People born in Monroe County, including politician Levi Scott, U.S. Representative from Illinois William Ralls Morrison, diplomat and lawyer Lansing B. Mizner, .
More notable people
- Timothy William Stanton (American geologist and paleontologist (1860-1953)) he was born in 21/09/1860
Other places with the same name (16)
- Monroe County, New York county in Florida, United States with a population of 740,900 people.
- Monroe County, Pennsylvania county in Pennsylvania, United States with a population of 170,154 people.
- Monroe County, Michigan county in Michigan, United States with a population of 150,568 people.
- Monroe County, Indiana county in Indiana, United States with a population of 148,219 people.
- Monroe County, Florida county in Florida, United States with a population of 73,900 people.
- Monroe County, Tennessee county in Tennessee, United States with a population of 47,177 people.
- Monroe County, Wisconsin county in Wisconsin, United States with a population of 46,582 people.
- Monroe County, Mississippi county in Mississippi, United States with a population of 35,123 people.
- Monroe County, Georgia county in Georgia, United States with a population of 28,042 people.
- Monroe County, Alabama county in Alabama, United States with a population of 20,459 people.
- Monroe County, Ohio county in Ohio, United States with a population of 13,586 people.
- Monroe County, West Virginia county in West Virginia, United States with a population of 13,229 people.
- Monroe County, Kentucky county in Kentucky, United States with a population of 10,549 people.
- Monroe County, Missouri county in Missouri, United States with a population of 8,672 people.
- Monroe County, Iowa county in Iowa, United States with a population of 7,770 people.
- Monroe County, Arkansas county in Arkansas, United States with a population of 6,584 people.
Illinois Other Counties (more counties)
| County Name | Population | Title |
|---|---|---|
| Cook County | 5,108,284 | County in Illinois, United States |
| Chicago | 2,677,643 | The third most populous city in the United States and the center of the Chicago metropolitan area. |
| DuPage County | 917,481 | County in Illinois, United States |
| Lake County | 693,593 | County in Oregon, United States |
| Will County | 688,726 | County in Illinois, United States |
| Kane County | 531,010 | County in southern Utah, United States |
| McHenry County | 305,888 | County in Illinois, United States |
| Winnebago County | 281,295 | County in Illinois, United States |
| Madison County | 262,635 | County in Montana, United States |
| Saint Clair County | 258,046 | The County of St. |
| Champaign County | 209,192 | County in Illinois, United States |
| Aurora | 196,383 | The second most populous city in Illinois. |
| Sangamon County | 193,882 | County in Illinois, United States |
| Peoria County | 177,652 | County in Illinois, United States of America |
| McLean County | 171,256 | County in North Dakota, United States |
| Naperville | 147,986 | The second most populous city in Illinois. |